(Original keynote slides can be found at https://github.com/Endran/PublicSlides) For years the industry standard of mocking on the JVM has been Mockito. Mockito is a wonderful library that really speeds up your testing by allowing you to create mocks in a very simple way. That being said, it does have its drawbacks, for which different strategies need to be deployed to keep your code testable. The main drawbacks are statics and finals. Final classes cannot be mocked, nor final methods, and also static methods are a no-go. To work with these type of things we need to wrap it, and copy the signature in a non final, non static way. I have a great adversity against statics, I've devoted an entire post about it, in short; It hides dependencies and brings so little convenience at the costs of its drawbacks. Finals on the other hand have purpose, it helps messaging the goal of a class or method. Java is one of the few languages where classes and methods are open/virtual by default and have to be closed/final by explicit action. In (for example) Kotlin, everything is final by default, if you do not want something to be final, you should use the open keyword. No matter if you follow the principle of making things final, static or not, if you are using Mockito the decision has been made. This mocking framework demands that everything is non-final, demands that everything is designed to be extended, since it might need to be mocked away. We should be able to improve upon this, and by the name of this post, you should be able to guess which framework will save the day. JMockit will help us with our impediments, and will give some other nifty benefits as well!